Fire-control apparatus



March 15 1927. 1,621,201

J. B. HENDERSON- FIRE CONTROL APPARATUS Original Filed July 26. 1919 2Sheets-Sheet 1 F'Lgl INVENTOR. Mp, B/LJLM AT ORNEYS.

March 15 1927. v

r J. B. HENDERSON FIRE CONTROL APPARATUS Original Filed July 26. 1919 2Sheets-Sheet 2 IN V EN TOR.

M15 ORNEYS.

zwzsz/wzwm By HMQL, 15,

UNllED STATESQ JAMES BLACKLOCK HENDERSON, OF BLACKHEATH, ENGLAND.

FIRE-CONTROL Original application flled July 28, 1919, Serial No.

APPARATUS.

318,542, and in Great Britain November 25, 1915.

Divided and this application filed September 16, 1924, Serial No.738,027. Renewed July 28, 1926.

My co-pending application referred to above relates to sighting devicessuch as gun sights, bomb-dro pers, range finders, position finders, artioial horizons, or in general any optical sighting device for use onboard ship or on an airship or aeroplane or on any other movingplatform, by which the effects of the angular motion of the ship,aeroplane or platform are eliminated so that the image of the target orother object viewed through the telescope may be stationary in the focalplane of the telescope irrespective of its angular motion, the externalobject being designated as the target and the moving plat- 1 form beingdesignated as the ship.

' More particularly the apparatus disclosed in the application consistsof a sighting device having a frame or casing adapted to be carried on aship, aeroplane or angularly moving platform so that it shall partake ofthe angular motion thereof, there being a telescopic optical system, afire-control apparatus and a stabilized gyroscope.

The telescopic system has optical parts which are under the control ofthe stabilizing gyroscope, whereby a distantly viewed Ob]Ct ismaintained in the telescopic field of View despite the movement impartedto other parts of the telescopic system' by the rolling pitching oryawing of the craft.

Similarly, the fire-control apparatus is responsive to both thegyroscopic control and to motion derived from the ship, or angularlymoving platform, said fire-control apparatus including an electricswitch for firing the guns.

This application relates particularly to the fire-control features of myco-pending ap-. plication referred to above articularly with respect tocontrolling the 'ring of guns or other pieces of ordnance atpredetermined positions durin the natural movements of the ship on w ichthey are mounted, the compensation for the effect of straying of thegyroscope on the time of firing and the provision of optical means fordetecting straying in order that such compensationmay be made.

The particular nature of the invention, as well as other objects andadvantages thereof will appear more clearly from a description of apreferred embodiment as shown in the accompanying drawings in which Fig.1 is a central elevation through a fire-conti ol apparatus constructedin accordance with the invention. Fig. 2 is a sectional elevationapproximately along the line 22 of Fig. 1. Fig. 3 is an end view of Fig.1 with part of the casing removed to more clearly show the opticalparts. Fig. 3 is a plan view of the-telescope portion of the apparatus.

The main frame of'the telescope consists of a disc 1, carrying acircular tubular projection 2 which serves as the case of the telescopeand also as the support of the instrument because this tube screws on tothe bracket 3 which is mounted on the sight pedestal. The telescopeconsists of the ob jective 4 and the eyepiece 4 (Fig. 3) carried by thering 5 which fits on the outside of the tube 2 but is capable of-beingturned relatively to this tube, oval slots being cut in the tube to passthe telescope beam. The prisms 6 and 7 of the telescope arerigidiyattached to the prism plate 8 which is pivoted on the frame 1 on theball bearing 9. Compound with the rism plate but on the opposite side ofthe disc 1, is the cylinder 10. The prism plate and cylinder 10 arestabilized by a gyroscope in its casing 11 (Fig. 1) which fits into aring 11 supported on a horizontal trunnion axis 12' on the gimbal ring13 so that the gyro rotor axis is approximately vertical. The gimbalring is supported at one end by the trunnion 14 which slides into theprism plate axially and at the other end by a trunnion 15 which slidesaxially in a bearing lfi, supported from the disc 1 by the U bracket 17.The gyro 11 and its supporting ring 11, have small gravitationalstability on the trunnions 12 due to the weight 31* andthe trunnion axis12 is below the level of the trunnion axis 14.-15 so as to giveincreased stability about the latter axis. I

The prism plate 8 has an angular adjustment relatively tothetrunnion14of the gimbal ring. This may be brought about in several different waysbut in Fig. 1 it is brought-about by a roller 18 carried by a shortpillar 19 attached to the gimbal, ring 13. This roller engages in ahelical slot in the cylinder 10' so that when the gimbal ring is slidbodily in the direction of the axis of the trunnion 14-15, the prismplate turns about the axis of these trunnions. This translation of thegimbal ring as a whole is brought about by .the screw 20 which rocks thelever 21 about its fulcrum on pillar 22 and moves the upper end of thelever to the right or left according as the screw 20 is screwed in orout. The upper end of the lever 21 bears against a ball centre attachedto the gimbal ring, concentric with the trunnion 14, and the similarlever 23 presses against a similar ball centre concentric with thetrunnion 15. The spring 25 acting through the lever 23 and its fulcrumon the pillar 24 serves to keep the gimbal ring always pressed againstthe lever 21 and the lever 21 pressed against the screw 20.

The gyro 11 can be caused to precess about the trunnion axis 12 by meansof the handle 27 which fits on the end of the trunnion 15, outside thecover 26. It can also be caused to precess about the trunnion axis 1415by means of one or other of the two levers 28 which can be turned by thecam 29 and the- 'nions 1415, and carries the prism plate 8 with it. Thisprecession 1s only used as a very rough adjustment, the screw 20providlng the fine adjustment. The gyro rotor axis is kept approximatelyperpendicular to the gimbal ring 13 by means of the handle 27, therelative position of the gyro case and gimbal ring being indicated bythe pointers and scales 31 (Fig. 1) which are visible through thewindows 32 in the outer cover 26.

The'electric current may be led into the gyro by flexible insulatedconnections at each trunnion or by insulated spring plug connectionsincorporated in the trunnions',.but which since they form no part ofthis invention are not shown in the drawing.

The switch controlling the firing circuit of a gun consists of a switchplate 33 which is pivotally mounted on a cylindrical sleeve 34 on thedisc 1 concentric with the disc. A small angular motion of the switchplate 33 round the disc centre can be brought about by means of the pin35 which projects through a slot in the disc. The switch plate carriesthe levers 36 and 37 which arepivotally mounted on their respectivefulcra' 38 and 39 and are interconnected by the link 40, so that a smallangular motion of lever 36 produces a larger angular "motion of lever37. The angular motion of the lever 36 is produced by the trigger 41which is carried by the cylinder 10 engaging with oneor other of the twosmall pins 42-43 on the lever 36. A small angular motion of the lever isthus produced after the manner of an escapement. The lever 37 carries,insulated on its end, the fork 44 which supports a small metal cross 45on pivots 46 and the cross carries two small rollers 47 and 48 attachedto a common spindle passing through the cross. The rolland also from theswitch plate 33 by which I they are carried. The line of insulationbetween the two segments is seen-in Fig. 2 to be inclined to the lever37 in its central position so that during the motion of this lever theroller 47 is for a short time touching the plate 49 while the roller 48is touching the plate 50.v The spindle of the two rollers then serves asthe electrical connection between the two plates and closes the firingcircuit either directly or throu h arelay.

The motion of the switch p ate about the sleeve 34 serves to bring theclosing of the firing circuit into hase with'the passage of the targetacross the cross wires of the ordinary layers telescope in directorcontrol.

When the sight is mounted directly on a gun I may app y a tangent screwadjustment to this motion of the switch plate and graduate the tangentscrew in ranges. If the telescope be kept on the target after'settingthe range and if the gun he slowly elevated it will fire when it reachedthe proper elevation for the particular range of the target. The opticaladvantages of the above ar-' rangement of telescope over those describedin my revious British Patents Nos. 3,683 and 6,9 7 of 1915 are (1) theobjective and e epiece are normally on the samevv level and t e parallaxerror due to any angular motion of the disc 1 round the trunnion 14 isless than it would be if the objective and eyepiece were not normally onthe same level, (2) with the prisms stabilized so that the telescopebeam always enters and leaves the prisms perpendicular to the surface ofthe glass the chromatic aberration, produced by the risms is constantand can be compensated by a suitable want of acromatism in theobjective, (3) the objective and focal plane are brought as close aspossible to the axis of the instrument commensurate with a given focallength and a given length of instrument parallel to the trunnion axis.By

elongating the cylindrical case of the telescope the diameter of thecase may be reduced and so the objective and focal plane may be broughtcloser to the axisand by rearranging the parts both cross wires andobje'ctive might be placed on the axis and both incorporated in thestabilized system.

I claim:

1. In gun-fire control apparatus, an angularly movable frame, agyroscope pivotally mounted therein and displa'ceable longitudinally ofa pivotal axis of its mounting in the frame, target position indicatingmeans,

an electric switch having relatively movable contacts, actuatingmechanism for said switch under the joint control of said frame toadjust said target. position indicating means and the switch contacts.

2. In gun-fire control apparatus, an any gularly movable frame, a gimbalring pivotally and slidably mounted therein, a gyroscope mounted tostabilize said gimbal ring, an electric switch having relativelymovablecontacts, switch-actuating mechanism comprising a triggerunderthecontrol of said gilnbal ring and yielding members operable by themovement of said frame to react against said trigger, and means to slidesaid ring thereby causing said switchactuating mechanism to adjust saidswitch contacts.

3. In gun-fire control apparatus, an angularly movable frame, a gimbalring pivotally and slidably mounted therein, a gyroscope carried by saidgimbal ring, an elec tric switch, switch-actuating means comprising a.trigger controlled by said gimbal ring and a yielding oscillatory memberconnected to said switch and operable by relative movement of said frameand gyroscope to react against said trigger, target position indicatingmeans and means responsive to a sliding motion of said gimbal ring'toadjust said switch to said target indicating means.

- 4. In gun-fire control apparatus, an angularly movable frame, a gimbalring pivotally and slidably mounted therein, a gyroscope stabilizingsaid gimbal ring, means urging said gimbal ring in one direction, targetposition indicating means, an electric switch, switch-actuatingmechanism, comprising a trigger controlled by said gimbal ring and ayielding oscillatory member connected to said switch and operable byrelative movement of said frame and gyroscope to react against its saidtrigger, shifting j means to move said gimbal ring against its saidurging means and means responsive to said shifting means to relativelyadjust said switch and target position indicating means.

5. In gun-fire control apparatus, an angularly movable frame, a gimbalring slidably mounted therein, a gyroscope for stabilizing said gimbalring, an electric switch, and switch-actuating mechanism comprising atrigger and an oscillatory member operable to react one against theother and one of which has a stabilizing connection with said imbalring.

6. n n-fire control apparatus, an angularly movable frame, a gimbal ringslidably mounted therein, a gyroscope mounted to stabilize said "imbalring, an electric switch, an adjustalfi trol of said gimbal ring andswitch-actuating means com rising a trigger and an oscillatory memroperable to react one a ainst the other and one of which is mount- 0 onsaid adjustable member, the latter e member under the con-'- beingresponsive to a sliding of said gimbal ring to adjust saidelectric'switch.

7. In gun-fire control ap aratus, an angul'arly movable frame, a gimbalring slidably mounted therein a gyroscope mounted to stabilize saidgimbal ring, gimbal ring shifting means automatically'operable in onedirection, a regulatory control for the ring operable in the reversedirection, an electric switch, and switch-actuating mechanism. under thecombined control of said 'mbal ring and frame stabilized in part, y theformer-and adjustable by a sliding movement of said gimbal ring.

8. In gun-fire control apparatus, an angularly movable frame, a gimbalring slida ly mounted therein, a gyroscope mounted to stabilize saidgimbal ring, an GIGCtIlOSWltCll,

actuating means therefor operable by rela tive movement of said frameand 'mbal ring, and regulatory elastic gimba ,ring shiftin meansoperable to effect an adjustment 0 said switch.

9. In gun-fire control apparatus, an angularly movable frame, anelectric switch, andswitch actuating means gyroscopically stabilized inpart and responsive to angular movements of said frame, said switchcomprising adjacent insulated contacts, a movement-multiplying arms anda' plurality of separated electrically connected contacts movable bysaid arm into en agement with one or a plurality ofsaid rst mentionedcontacts.

10. In gun-fire control apparatus,an angularly movable frame, anelectric switch, a

support therefor adjustably secured to said frame, and switch-actuatingmeans gyroscopically' stabilized in part and responsive to angularmovements of said frame, said switch comprising electrically separatedcontacts stationary with respect to said switch support, amovement-multiplying arm and a plurality of electrically connectedrollers adapted to be positioned to spanthe separation of said-firstmentioned contacts or to engage a single one thereof.

11. In gun-fire control apparatus, an angularly movable frame, agyroscope p votally mounted therein to be capable of being shifted withrespect thereto, target position indicating means, an electric switch,and actuating mechanism therefor under the joint control of said frameand gyroscope and an adjusting connection between said gyro scope andtarget osition indicating means operable by a shi ting of the former toadjust the latter.

12. In gun-fire control apparatus, an angula-rly movable frame, agyroscope pivotally mounted therein -to be capable of being shifted withrespect thereto, target position indicatingmeans', an electric switchhaving relatively movable contacts, and actuating means thereforunder-the joint control of said frame and 'yroscope operable by ashifting of the litter to adjust the relatively movable switch contacts.

13. In fire-control apparatus for use on an angularly displaceablesupport, a telescope provided with a movable reflecting 'device, agyro'sco e, a mounting therefor adapted to be sta iliz'ed thereby, afiring gear including a pivotally' mounted element yieldingly combinedwith said gyroscope mounting and operatively connected to saidreflecting device, a trigger carried by said element, and means operableto relativel displace said mounting and element to e fect simultaneousadjustment of said reflectin device and trigger.

14. n fire-control ap aratus for use on an angularly displaceab esupport, an adjustable optlcal system, a firing gearoperatively-connected with said system and comprising a pivoted member,a trigger carried thereby, an escapement co-acting with said trigger, alever actuated by said escapement,

, gear comprising a bridging contact having terminals spaced from eachother on an axial line, mutually insulated contacts adapted to bespanned by said bridging contact and being electrically separated fromeach other along a line placed at an I angle to said axial line on whichthe spaced terminals of said bridging contact 'are 10- I cated, agyroscope, and means subject to a joint control by the angular-1ydisplaceable support and said gyroscope operable to relate said bridgingcontact with one or more of said mutually insulated contacts.

16. In fire-control apparatus for use on an angularly displaceablesupport, a frame, a telescope provided with a movable reflecting device,a gyroscope, a gimbal ring therecam and follower relation between saidgimbal ring and element to adjust said reflecting device and firinggear.

17. In fire-control apparatus for use on an angular-1y displaceablesupport, a frame,

'a te escope provided with a movable reflecting device, a gimbal ring,trunnions therefor slidably mounting the same with respect to saidframe, a gyroscope pivotally mounted in said gimbal ring adapted tostabilize the latter. a firing gear comprising a pivoted elementcontrollingly connected with said reficctin device, a cam and a followertherefor one eing associated with said element and the other with saidgimbal ring, means'to actuate said cam and follower to effect adjustmentof said firing gear and refiector, means for precessing the gyroscopeabout the axis of the gimbal ring trunnions and means for precessing itabout the axis of its own pivotal support.

18. In fire-control agparatusfor use on an angularly displacea lesupport, a frame movable about an axis as the support is displaced, anadjustable telescopic system and a stabilizing gyroscope ounted in saidframe, a firing gear under the joint control of said frame and gyroscoand comprising va bridging contact having s aced apart contact-makingportions, mutua y insulated contacts adapted to be singl engaged andelectrically connected by sai bridging contact at different times, said.mutually insulated contacts beingvelectrically separated along a lineplacedangularly to a median line extending through the contact-makingportions of said bridging contact when the latter electrically connectssaid mutually insulated contacts, and means for adjusting thetelescopic, system and the firing gear contacts. v

In testimony whereo'fI aflix my signature.

JAMES BLACKLOCK HENDERSON.

